I feel like there is some kind of underlying lesson that we, OpenGL app programmers, should be getting out of this...<br><br><div>What about a psuedo-database of app -> extension list rather than by year? Surely Quake3 doesn't make use of but <= 10 extensions. I'd imagine the same holds true for other old games as well. A simple "strings" on their binary could figure that out...<br> <div><br><div class="gmail_quote">On Fri, Mar 11, 2011 at 2:14 PM, Kenneth Graunke <span dir="ltr"><<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"> <div><div></div><div class="h5">On Friday, March 11, 2011 10:46:31 AM José Fonseca wrote:<br> > On Fri, 2011-03-11 at 09:04 -0800, Eric Anholt wrote:<br> > > On Fri, 11 Mar 2011 10:33:13 +0000, José Fonseca <<a href="mailto:jfonseca@vmware.com">jfonseca@vmware.com</a>><br> wrote:<br> > > > The problem from<br> > > ><br> > > > <a href="http://www.mail-archive.com/mesa3d-dev@lists.sourceforge.net/msg12493.h" target="_blank">http://www.mail-archive.com/mesa3d-dev@lists.sourceforge.net/msg12493.h</a><br> > > > tml<br> > > ><br> > > > is back, and now a bit worse -- it causes Quake3 arena demo to crash<br> > > > (at least the windows version). The full version works fine. I'm not<br> > > > sure what other applications are hit by this. See the above thread for<br> > > > more background.<br> > > ><br> > > ><br> > > > There are two major approaches:<br> > > ><br> > > > 1) sort extensions chronologically instead of alphabetically. See<br> > > > attached patch for that<br> > > ><br> > > > - for those who prefer to see extensions sorted alphabetically in<br> > > ><br> > > > glxinfo, we could modify glxinfo to sort then before displaying<br> > > ><br> > > > 2) detect broken applications (i.e., by process name), and only sort<br> > > > extensions strings chronologically then<br> > > ><br> > > > Personally I think that varying behavior based on process name is a<br> > > > ugly and brittle hack, so I'd prefer 1), but I just want to put this<br> > > > on my back above all, so whatever works is also fine by me.<br> > ><br> > > If this is just a hack for one broken application, and we think that<br> > > building in a workaround for this particular broken application is<br> > > important (I don't), I still prefer an obvious hack for that broken<br> > > application like feeding it a tiny extension string that it cares about,<br> > > instead of reordering the extension list.<br> ><br> > There are many versions of Quake3 out there, some fixed, others not, and<br> > others enhanced. This means a tiny string would prevent any Quake3<br> > application from finding newer extensions. So I think that if we go for<br> > the application name detection then we should present the whole<br> > extension string sorted chronologically, instead of giving a tiny<br> > string.<br> ><br> > Jose<br> <br> </div></div>I agree with José - it's not one broken application, it's a number of old,<br> sometimes closed-source games that we can't change.<br> <br> I'm not sure how changing the sorting solves the problem, anyway - the amount<br> of data returned would still overflow the buffer, possibly wreaking havoc. I'd<br> rather avoid that.<br> <br> Ian and I talked about this a year ago, and the solution I believe we came up<br> with was to use a driconf option or environment variable:<br> <br> If MESA_MAX_EXTENSION_YEAR=2006, then glGetString would only return extensions<br> created in 2006 or earlier. The rationale is that if a game came out in 2006,<br> it won't know about any extensions from 2007 anyway, so advertising them is<br> useless. The fixed-size buffer is also almost certainly large enough to handle<br> this cut-down list of extensions.<br> <br> This should be trivial to do now that you already have the years for each<br> extension...just store them in the table, rather than in comments, and check<br> before listing an extension.<br> <br> A driconf option is nice because it allows this to be overridden in .drirc on<br> a per-app basis, rather than having to set an environment variable. It might<br> be a bit more work though.<br> <font color="#888888"><br> --Kenneth<br> </font><div><div></div><div class="h5">_______________________________________________<br> mesa-dev mailing list<br> <a href="mailto:mesa-dev@lists.freedesktop.org">mesa-dev@lists.freedesktop.org</a><br> <a href="http://lists.freedesktop.org/mailman/listinfo/mesa-dev" target="_blank">http://lists.freedesktop.org/mailman/listinfo/mesa-dev</a><br> </div></div></blockquote></div><br></div></div>